by Judith Curry
Here is a synopsis of some recent papers and other issues in the Arctic
For background, previous threads on the Arctic:
- Pondering the Arctic Ocean. Part I: Climate Dynamics
- Arctic update
- Likely causes of the recent changes in Arctic sea ice
Permafrost thaw – just how scary is it?
Arctic permafrost, and the possibility of massive methane releases into the atmosphere, has been in the news this past week. The Washington Post has a good overview of the issue with all the relevant links, in this article entitled Permafrost thaw – just how scary is it? Some excerpts:
One of the least understood — and one of the more unnerving — facets of climate change is the question of what will happen as the Arctic region heats up and permafrost in places like Alaska and Siberia thaws out. It’s a potent feedback mechanism, and scientists still aren’t sure just how potent it might be.
Meanwhile, Gillis’s piece — and the Nature survey — largely dealt with carbon that’s frozen in the northern soils. There’s a separate, though related, issue of what happens with the methane locked in frozen hydrates that’s buried in ocean sediment. There are thousands of gigatons of methane beneath the seas, comparable to the amount of carbon contained in the Earth’s coal deposits. And, as the Arctic waters warm, some of this methane is likely to bubble up into the atmosphere. Another troubling feedback.
So how worried should we be? Over the weekend, Justin Gillis had a beautifully reportedpiece in The New York Times on the permafrost question that summed up what scientists do and don’t know: “In the minds of most experts, the chief worry is not that the carbon in the permafrost will break down quickly — typical estimates say that will take more than a century, perhaps several — but that once the decomposition starts, it will be impossible to stop.” There’s no looming apocalypse, but melting permafrost could make it much harder to avoid setting the planet down a path of irrevocable warming.
The problem is that scientists have had similar difficulties getting a handle on just how much methane actually is bubbling up, since the Arctic isn’t exactly an easy place to take measurements. It can also be unclear whether observed methane plumes are new developments related to current warming or long-standing natural trends. At the moment, despite some frightening headlines in the British press, there doesn’t seem to be a “methane time bomb” ready to go off. Read Andy Revkin or University of Chicago ocean chemistDavid Archer for more context here. There’s no need for lurid Hollywood disaster-movie scenarios. The reality of what’s actually transpiring is apocalyptic enough.
Drilling for oil in the Arctic
BOEM conditionally approves Shell Arctic drilling . Some excerpts:
The federal Bureau of Ocean Energy Management on Friday conditionally approved a plan by a subsidiary of Royal Dutch Shell to drill exploration wells in the Chukchi Sea off Alaska’s northwest coast.
One condition will be lopping 38 days off the drilling season to make sure the company has enough time to cope with a spill or a wellhead blowout before sea ice moves into the drilling area.
Canada National Energy Board keeps Arctic drilling provisions. Some excerpts:
Canada’s National Energy Board said on Thursday that any company that wants to drill for oil and gas in Arctic waters will need to demonstrate it has the capacity to sink a relief well in the same drilling season to cope with possible well blowouts.
In Russia, oil spills are ravaging habitats. Some excerpts:
On the bright yellow tundra outside this oil town near the Arctic Circle, a pitch-black pool of crude stretches toward the horizon. The source: a decommissioned well whose rusty screws ooze with oil.
Environmentalists estimate that at least 1 percent of Russia’s annual oil production, or 5 million tons, is spilled every year. That is equivalent to one Deepwater Horizon-scale leak about every two months. Crumbling infrastructure and a harsh climate combine to spell disaster in the world’s largest oil producer, responsible for 13 percent of global output.
Oil, stubbornly seeping through rusty pipelines and old wells, contaminates soil, kills all plants that grow on it and destroys habitats for mammals and birds. Half a million tons every year enter rivers that flow into the Arctic Ocean, the government says, upsetting the delicate environmental balance in those waters.
Interannual to decadal variability of Atlantic Water in the Nordic and adjacent seas
J.A. Carton, G.A. Chepurin, J. Reagan, S. Hakkinen
Abstract. Warm salty Atlantic Water is the main source water for the Arctic Ocean and thus plays an important role in the mass and heat budget of the Arctic. This study explores interannual to decadal variability of Atlantic Water properties in the Nordic Seas area where Atlantic Water enters the Arctic, based on a reexamination of the historical hydrographic record for the years 1950–2009, obtained by combining multiple data sets. The analysis shows a succession of four multiyear warm events where temperature anomalies at 100 m depth exceed 0.4°C, and three cold events. Three of the four warm events lasted 3–4 years, while the fourth began in 1999 and persists at least through 2009. This most recent warm event is anomalous in other ways as well, being the strongest, having the broadest geographic extent, being surface-intensified, and occurring under exceptional meteorological conditions. Three of the four warm events were accompanied by elevated salinities consistent with enhanced ocean transport into the Nordic Seas, with the exception of the event spanning July 1989–July 1993. Of the three cold events, two lasted for 4 years, while the third lasted for nearly 14 years. Two of the three cold events are associated with reduced salinities, but the cold event of the 1960s had elevated salinities. The relationship of these events to meteorological conditions is examined. The results show that local surface heat flux variations act in some cases to reinforce the anomalies, but are too weak to be the sole cause.
Citation: JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 116, C11035, 13 PP., 2011 doi:10.1029/2011JC007102 (link to abstract and partial figs)
- Nordic Seas region is subject to strong decadal ocean variability
- The ocean variability is mainly due to changes in the inflow of Atlantic Water
- The most recent anomaly began in 1999, is massive, and continues
- Solar and volcanic impacts
- Ocean heat transport
- Arctic teleconnection regimes (e.g. AO)
- Aerosol and GHG effects
- Feedbacks initiated by all of the above